Getting rep with AV is no harder for Horde than it is for Alliance, even with losses.
Look at it this way, in alot of the battlegroups Horde queue time is instant to five minutes for AV. Alliance often wait over 45 minutes to get in. You lose in 20-30 minutes, do all your turnins, kill Lolinda and as many officer NPCs as possible and you re-queue instantly. Gaining rep with AV is a joke, even as Horde. It took me two weeks to go from neutral to exalted and I think I won maybe 2 or 3 times.
As far as the lack of wins, the same logic applies. The bonus honor is better with 20 minute losses than two to three hour wins due to the instant queues.
My prediction is that Horde will change once the PvP system is revamped and you only get tokens for winning a match. Winning AV as Horde is not hard, most Horde that do AV more than a few times know the strategies to win. It's just there is just very little incentive to do so right now, unless you still have the quest to kill Van.